Heating unit



June 27, 1967 K. H. BRosENius 3,327,947

HEATING UNIT Filed Feb. 8, 1965 2 Sheets-Sheet l Fig.1 Fig2 Figi NAi-2 7 @l /W/ /f// n INVENwR KARL Hmome BRosEmus ATIU'RNEY :2l Sheets-Sheet 2 Fig. 8

June 27, 1967 K. H. BRosENlUs HEATING UNiT Filed Feb. a, 1965 INVENTR KARL H|LD|-6 BRosEmus ATTORNEY United States Patent O HEATING UNIT Karl Hilding Brosenius, Villa Jagarbacken, Djurgarden,

Stockholm, Sweden Filed Feb. 8, 1965, Ser. No. 430,889

Claims priority, application Sweden, Feb. 10, 1964, 1,625; Aug. 19, 1964, 10,019 2 Claims. (Cl. 237-16) The .present invention relates to a heating unit, particularly for private homes or one-family (or two-family) houses which are warmed by hot water radiator systems. Conventional heaters for private homes usualy consist of a heating boiler which contains either one or two furnaces (simple furnace or double furnace) and also la hot water heater of the percolator or s-torage type to furnish the household with hot water. The furnaces with their appurtenant fume or flue pasageways and also the hot water lsupply unit by conventional heaters are mutually surrounded by the water Itank of the boiler said tank in conventional lboilers for private homes usually containing about 1510-250 liters of water. The boilers are usually located separately in a cellar room which nowadays often is small. The water is heated by means of a furnace (or more furnaces) using a suitable fuel (-such as oil, wood, coal, etc.) and it then transfers part of its heat to the remaining part Iof the house via the hot Water radiators. The ue gases generated in the burning process are passed off `through a chimney.

The ratio of the useful heat actually obtained to the a-mount of heat which would be obtained in complete combustion of the fuel used will be referred to as the eiliciency of the heating system. This eiciency is rather low for conventional private home heaters especially when averaged over the entire year. For example, extensive investigations in Sweden have :shown tha-t the efliciency of oil burning heaters when averaged over an entire year is only 50% for presently installed systems and it is calculated that newer types of single house heaters can attain an efficiency of about 65%. The rest of the energy (that is 50% for presently installed systems and 35% for systems of newer types) contained in the fuel burned is lost without supplying any useful heat to lthe household. The losses occur in various ways of which the following ones are most important: losses in the flue gasses produced while the fuel burns (this loss is seldom lower than radiation or insulation losses from the furnace and its various parts, and also draft losses through the chimney during non-burning periods, i.e. stand still periods. It is particularly significant that the total burning time for oil burners of small units is only a minor part of the total time, usually only 1A lto 1/5 of the total time. However the heater remains at a relatively high temperature all of the time (even during the summer for hot water supply system) and therefore losses through insulation and chimney draft during long standstill periods constitute a considerable part of the total annual loss.

The present invention makes it possible to considerably reduce the above named losses and also simplify and reduce Ilthe price of the heater. The heating eiciency according to the invention has been raised to 85% on an -annual basis. This is an extremely high value for small heating units and corresponds to a loss of only over a years use. The heater according to the present invention also has a number of additional important advantages which will be set out in the following description.

In the drawings:

FIG. l shows a side View in cross section of one embodiment of the invention.

FIG. 2 shows a front View in cross section of the embodiment of FIG. 1.

ice

FIG. 2a shows a plan view of a detail of the embodiment in FIG. 2.

FIG. 3 shows a vdetailed cross sectional front view of the furnace portion of the embodiment in FIG. 1.

FIG. 4 shows a cross sectional front view of an embodiment including a double furnace.

FIG. 5 shows a cross sectional plan view of the embodiment in FIG. 4.

FIG. 6 shows a cross sectional side view of a further embodiment ofthe invention.

FIG. 7 shows a cross sectional plan view of a heating block according to the invention completely installed.

FIG. 8 shows a cross sectional plan view of a conventional boiler room.

FIG. 9 shows a cross sectional plan view of a conventional boiler room adapted to form a heating block according to the present invention.

FIG. 9a shows on a smaller scale a plan view of an installed heating block according to the present invention.

-One advantageous .and characteristic embodiment of the invention comprises a low, water cooled furnace 1 (FlGURES 1 and 2) with the smallest possible Water volurne (eg. about 25 -to 30 liters) and an accumulator 2 with a very lange water volume, e.g. 600-1000 liters. This accumulator is placed verticaly above the furnace and is separated from it by means of an insulation layer 3, but the water storage space in the accumulator is connected directly to the water space in the furnace by means of tube 4, 5. The water passageway -between the water 'space in the accumulator and the water space in the furnace is so constructed that heat can be transferred in only one direction from the furnace to the accumulator but not in the opposite direction. The hot water supply system for the house is located inside the accumulator and may be a hot water heater 7 of percolator type, or a water heater of storage type.

According to an especially yadvantageous embodiment of the invention the heat insulation against the surroundings both of the accumulator section and of the furnace section is made as a filling 8 of loose insulating material applied at the building site between the surfaces of the accumulator section and the furnace section on one side and surrounding walls in the building on the other side. The walls are arranged with a suitable space from the surfaces of the accumulator and the furnace.

According to one feature of the invention, the normally coupled furnace and accumulator parts can be simply disconnected from each other. This is especially advantageous since the accumulator is directly connected to the buildings circulation system for radiators, hot water, etc., and in this way the furnace, which has the shorter life time, can be replaced without disturbing the remaining p-art of the circulation system.

From the above remarks it can be seen that the heater according to the present invention differs from conventional private home units at least in the following ways:

(l) The furnace section and the major water storage section do not form a single unit but consist of two separa-te units heat insulated from each other but coupled together by -means of two tubes or pipes.

(2) The water storage capacity of the accumulator is considerably greater than in conventional heaters and about 10-30 times greater than the water capacity of the furnace section, which is extremely small.

(3) The heat insulation of both sections of the heater is not normally carried out in the factory but at the place of installation in much the same way as walls and floors are furnished with insulation filling at a construction site.

(4) The heater is-at least at cellar-less liouses-not installed in a separate furnace or hea-ter room but is combined with the heater room Walls to a heating block, which can be located in any of several different places in the building. This arrangement increases the efficiency of the system.

(5) The furnace section is detachable from the remaining portion of the heating unit.

The first major component of the heater, the furnace section of the invention, may be constructed in various ways. However its height should be small in relation to its heating surface areas. By restricting the height of `the furnace section, one leaves room for an accumulator tank of largest possible volume to be placed over the furnace without exceeding the height clearance available in a cellar boiler room for example.

The furnaces shown in FIGURES l-4 may be described most simply as a double-walled box with a rectangular or circular horizontal cross-sectional shape for exa-mple and with a slight space, e.g. 2 cm. between the outer and inner plate walls. This space is filled with water. One or two doors are connected to the front of the box depending on whether the furnace is a simple furnace or a double furnace. Two types of fuel such as gas and solid fuel can be used with the double furnace.

FIGURES 1-3 show an embodiment with a simple furnace. It consists of an inner sheet iron surface 11 and outer surface 12 with a water filled space 6 about 2 cm. thick between them. These vertical inner and outer walls 11, 12 are joined at the top to one or more (three as shown in FIGS. l-3) water filled, double Walled covers of plate material 14, 15, 16. The water contained in these covers is in circulatory connection with the water contained in the vertical walls of the unit. Two lower covers 14 and 15 as shown in FIG. 3 are arranged in a zig-zag relationship and flue gas outlet 17 is connected to the uppermost cover 16.

The front side Iof the furnace is furnished with a flue dust lid 21, with its appurtenant outlet channel 22 through which the soot collecting between the covers is removed.

FIGURES 4-5 show an embodiment of the furnace of the double furnace type. This embodiment differs from that of FIGURES l-3 mainly in that it may have a somewhat wider front dimension and be furnished with two furnace outlet channels 27, 28 with lids 29, 30 leading to two furnace spaces V and H. These two furnace spaces are separated by an additional wall 31 and possibly by still another wall 32 to obtain a certain guiding of the fumes or flue gases. With this embodiment the furnace can be fed with more than one fuel, for example oil and wood or rubbish without readjusting the boiler. For ex a-mple an oil burner 33 may be mounted in the lid of the left section V while wood burning takes place in right section H.

The furnace arrangement according to the invention has, in contrast to most conventional boilers, furnaces small in the vertical direction but large in the horizontal directions. This means that long pieces of log or wood, rubbish, or the like can be burned without the trouble of first cutting or breaking it into small pieces. This is a considerable advantage when burning wood. Intermittent full draft burning during relatively long periods of time is possible because the excess heat is stored in the large amount 0f water in the accumulator and later can be withdrawn therefrom. This feature is not available in conventional furnaces.

In the simple furnace as well as in double furnace the fumes or flue gases flow from the outlet to a chimney. Two principle types of chimneys are of particular interest:

(1) In cellarless houses the chimney is often an insulated metal tube 34 to which flue gas outlet 17 from the furnace is connected as in FIG. l for example.

(2) With chimney made of masonry, for example in houses with cellars, the fume outlet 17 is connected directly to the liue gas passage 35 in the chimney as shown in FIG. 6.

In both cases the flue gases are heat insulated from the accumulator tank above the furnace. Thus, the chimney draft cannot act cooling on accumulator during stand Still periods of the furnace.

In both cases the connection between flue gas outlet 17 and chimney 34 or 35 is detachable so that the furnace section can be disconnected from iboth the chimney and the accumulator and the furnace can be removed without removing the accumulator or the chimney.

The second major component of the heater is the accumulator tank which essentially is a rather large water lled tank 2 of sheet metal (FIGS. 1 2). The accumulator contains near its top end a hot water heater 7 of the percolator or storage type which in the usual manner is connected to the hot and cold water system of the house. The hot water circulated by means of a pump to the radiator system in the house is withdrawn from near the top of the tank, e.g. at 37 and thereafter passes in the usual way lirst through a shunt valve 38 and then to the radiators and finally returns in a cooled condition near the bottom of the accumulator tank at 39.

The large accumulator Water tank is connected to the Small water storage volume of the furnace by means 0f normally two relatively wide tubes one of which is a rise tube 4 and another of which is a return tube 5. The rise tube 4 starts from a position near the top of the furnaces water storage compartment and discharges at a relatively high level in the accumulator. Hot water is supplied by self-circulation to the upper part of the accumulator during the firing periods in the furnace. The return conduit 5 sucks the cooler water from near the `bottom of the accumulator to the furnace. In this way water circulation between the furnace and the accumulator continues until the accumulator is lled with water at a predetermined high temperature. Then in case of automatically lired furnaces a thermostat controlled by the temperature of the accumulator stops firing and further heating ceases. When burning fuel such as wood, the firing of the furnace is stopped manually when the proper temperature is reached.

The tendency of water to rise when heated means that according to the self-circulation process of the invention the heat is transferred in one direction only, namely upward, by water circulation from the furnace to the accumulator. The heat which is once stored in the accumulator tank cannot subsequently be lost in downward direction to the more rapidly cooling furnace section by water circulation during stand-still periods. This also contributes significantly to the high efliciency attained by the invention.

Another valuable feature of the invention is that tubes 4 and 5 are coupled in a disconnectable manner at joints 40 and 41. These joints can be flange couplings or ordinary threaded couplings and partly due to space 3 between the furnace and the accumulator these couplings are easily accessible to coupling tools.

The accumulator tank at little extra cost can be prepared for or equipped with an electrical heating unit. In the former case it is only necessary to attach a 2" sleeve 43 (FIG. 2) in the accumulator. In the latter case a removable electrical heating cartridge is placed inside said sleeve. A second advantage is that the spacious accumulator tank gives sufficient room for a built-in electrical heating cartridge.

The third important component of the invention concerns the heat insulation of the heater. This insulation differs completely from that generally -used in conventional household furnaces. The insulation is characterized in that the insulation of the accumulator section as well as the furnace section is carried out at the place of installation according to much the same principles used in insulating walls and floors at building sites, that is the space between the heater units and certain adjacent walls of the building are lled with loose and inexpensive insulation material. The resulting insulation layer can be rather thick resulting in a high insulation effect. With conventional Ihousehold furnaces a comparatively thin insulation layer is installed at the factory and a protective shell of sheet metal or the` like must be installed over the insulation layer. The last named shell is unproductive from the standpoint of heat economy and also it is relatively easily damaged during delivery.`

Also in spite of its large water capacity, the accumulator can pass through ordinary door openings which would not permit the passage of heater units having the same water capacity but including conventional insulation layers. For locations with difficult transportation conditions it is a further advantage to be able to simply disconnect the furnace and accumula-tor sections. The weight of each section then is less than half the weight of a conventional household furnace which is quite heavy (usually at least 250-275 kg.) and` not infrequently causes troublesome transportation difficulties in the case of small houses.

The insulation of the heater according to the invention differs somewhat at houses with cellars and houses without cellars.

The most usual embodiment at cellarless houses, where the furnace room and living quarters are usually located on a single level, is for conventional heater rooms shown in FIG. 8. The presently most common furnace room in such a house is `constructed with the smallest possible surface area, e.g. 1.0 x 1.5 meters. The walls of the furnace room are often made of vertical Wooden joists 44 to which incombustible plaster sheets or the` like 45, 46 are attached. The door 47 to the entrance of the furnace room often opens outward. A conventional furnace room of this common type is shown in FIG. 8 in which the conventional furnace is shown a-t 48.

Such a furnace room is obviously well suited for heaters made according to the present invention. However, the furnace room can be further simplified by omitting the inner plaster sheets. Such a simplified furnace room is shown in plan view in FIG. 9. Its walls have a framework of vertical wooden posts with an outside layer of plaster sheets 45. Door 47 is placed, in this example, in the outer Wall. The installation of a heater according to the invention in such a room is commenced by placing the uninsulated heater in position 49 for example. After the heater has been placed in its proper position, the radiator pipes, circulation pump system, hot and cold water pipes, chimney tube, etc. are attached. The lead pipes, e.g. 50, 51 are vbrought in suitably in the space between the heater and the walls 45 and need not be individually insulated in this area because sufficient insulation is achieved when the loose insulation material is inserted. Finally a front plate (which may be made of two sections) 52, 53 is installed. The heater is now surrounded on all four sides by walls at a suitable distance (about 10 cm.). The space between the heater and the floor may be filled with insulating material 8a (FIG. 1) before the front plate is installed, while the remaining spaces will be filled fromabove with insulat ing material 8 (for example mineral wool) after the front plate has been installed. Finally, filling material 8b is placed over the accumulator tank. This insulating filling material will thus surround all connecting pipes and also the expansion vessel 54 (FIG. 2) mounted above the heater. The expensive separate insulation of connecting pipes and accessories in conventional systems is economically avoided.

ySince the necessary loose insulating materials are considerably cheaper than insulation sheets, mats, discs, etc. `which are used `in conventional prefabricated heaters, it is possible to use a much thicker layer ofinsulation according to the invention without excessive costs. A much' more effective insulation results. Nor` does Ythis extra insulation thickness increase the transportation volume of th'e heater.

After the insulation material has been installed according to the invention, the greater part of the furnace 6 room has been changed into a composite heating block B (FIG. 5 and FIG. 9A) instead of the conventional separately standing heater in a furnace room. The provision of this block opens the way to many advantageous arrangements which will be described below.

One remarkable advantage of the heating block is its increase in efficiency of the heating system. According to FIG. 9 three of the block walls border on the living quarters and therefore heat losses through these walls can be utilized in the building. In the conventional furnace room of FIG. 8 the heat lost through the furnace insulation is first transferred to the air in the furnace room on all sides of the furnace and then is lost because of chimney draft out through the chimney. Only a small part of this heat is finally utilized by the household.

Other characteristic advantages of the heating block will be described later.

In a house with a cellar, or in an older house with a conventional furnace, there is no separate furnace room of the type shown in FIG. 9. In such cases however a heating block can be easily provided by setting up the necessary walls. After the walls have been constructed the heater can be installed and the insulation material finally filled in between the heater and the walls as shown in l-"IGUREl 7.

Obviously the invention is not limited to the illustrated embodiments using walls with wooden frames and plaster sheets. The walls may vary according to local conditions and may be made of masonry, concrete blocks, sheet metal, tile, asbestos cement, plywood, etc. The invention allows one to choose both simple and more luxurious types of walls depending on the type of building.

'Now that the major components of the invention have been described, certain advantageous details will be cousidered.

Thus, a small radiator (about the size of a '1/2 m.2 panel radiator) may be connected by means of selfcirculation to the water storage space in the furnace.

This radiator 5S (see FIG. 1) is placed in a room, which should be heated by the heating system. This radiator functions in the following Way: Every time the furnace has been heated to its highest temperature in order to charge the accumulator with hot water, the radiator 55 by self; circulatioin (gravity circulation) absorbs heat from the furnace water and transfers the heat into useful heat in the room in which the radiator is placed. Thus, the furnace water will get cool faster, and the result is that the useless loss of heat from the furnace to the chimney draft during the cooling period will be considerably reduced. Thus, the radiator 55 also in this respect contributes to the high efficiency factor of the heater according to the invention.

A special arangement, which sometimes can be useful, is shown in FIG. 1 in which certain equipment for the heater, such as circulation pump 58, thermostat 59, shunt Valve 38, thermometer 60, safety valve 62, etc., are placed on one of the sides of the heating block, facing the (heated) living quarters instead of on the front side of the heater. This arrangement can facilitate readjustment-s or reading of the instruments, as they can be done directly from the living quarters. Also, the heat losses from these equipments will be utilized as useful heat to the living quarters.

According to the present invention where the insulation layer is bounded by 4surfaces constructed at the place of installation, it is very important to avoid placing holes in the surface for mounting elements. This would require much time consuming fitting work. It is preferable to mount the intruments atl the factory in spite of the fact that the insulation is first applied at the place of installation.

To accomplish this a part of the panel located in front of the heater is installed at the factory as a relatively small vertical strip of sheet material at a distance in front of the heater to allow room for the insulation layer. Necessary equipment, instruments, etc. can then be mounted on this strip at the factory. At the place of installation the remaining parts of the front wall can be attached to this premounted strip.

Another unique feature of the presen-t invention is the location of the instrumentation, etc. on the surface of the heating block which faces the living quarters (see FIG. 1) instead of on the front side of the heater. On the other hand, equipment such as the oil burner 20 (or possibly a gas burner) and the chimney damper handle are located on the front side of the heater. This arrangement has shown itself to provide extraordinary advantages not the least when compared with conventional placements.

This arrangement means that all instruments such as the thermostat, thermometers, shunt, etc. which ought to be handy for inspection and adjustment are placed within the living quarters. The control element can even be placed in the most elegant room of the home if this room happens to abut the heating block since it is not necessary to show more of the instruments than for example the knobs on a radio set. A readjustment of the shunt or thermostat which is often necessary does not require a visit to a furnace room. The living quarters are also freed from disagreeable sounds and odors which arise from the oil burning system. As can be seen in FIG. 9 the oil burning section is effectively separated from the living quarters by `the heating block itself. All dirty work, .such as the removal of soot, cleaning of the oil burner, etc. is effected from the outside. In this way wood burning, rubbish burning, etc. can be conveniently carried out without disturbing the living quarters.

The absence of instruments, pipes and the like on the front side of the heater considerably facilitates the formation of the front wall of the heating block. To a large extent this can be formed by a simple sheet 53 of plaster for example which can be set up as an ordinary inner wall after the heater has been installed. The only hole required in sheet 53 is the one allowing passage of the chimney damper handle 6I.

The lower part 52 of the front wall is placed nearer the furnace and can be made of sheet metal for example (see FIG. l).

The shunt valve, thermostat, thermometers, circulation pump, safety valves, etc. may be mounted (possibly at the factory) on any one of the three sides of the accumulator which face the living quarters (see FIGURES 1 and 9a). It is advantageous to concentrate this equipment on the accumulators upper part. The corresponding Wall of the heating block may be constructed with its lower part 10b comprising a fixed Wall of plaster board for example while the upper part 10a which covers the instrumentation area may be constructed as a partially or completely removable wall panel. Since this part of the wall is located in the living quarters and not in the furnace room, it may be constructed of combustible material such as plywood. Such a sheet (in contrast to incombustible material) can be easily cut to form holes, etc. which are necessary to make certain instruments available from within.

This arrangement has the further advantage that heat emitting elements such as the thermostat box, circulation pump, pipes and valves to the hot Water heater, etc. now face toward the living quarters and the heat they emit is no longer lost but is utilized by the household. In the conventional placement of these elements in the furnace room (a placement which is quite necessary with conventional furnaces) the heat from these elements, which is not insignificant, is wasted in the furnace room and eventually escapes through the chimney.

According to one embodiment of the invention the circulation pump, which pumps hot water from the accumulator via the shunt valve to the radiator system, is not continuously in operation but is coupled via a room thermostat which allows the room temperature to govern the amount of heat which is supplied to the radiators. In this way the room temperature can Ibe maintained at a temperature which can beset on the room thermostat. The daily regulation of the room temperature thus is not accomplished by frequent adjustment of the shunt valve. Instead the shunt is adjusted only seasonally so that for example during the winter time the accumulator will deliver circulation water of high temperature, while during the spring and fall it will deliver water of a suitably lower temperature. However at all these times the temperature of the water is so high that the house would receive too much heat if the pump operated continuously. Since the thermostat occasionally stops the circulation it is possible to obtain the desired room temperature set on the thermostat. The seasonal adjustment of the shunt permits an evener heat supply than if regulation was obtained only by the operating times of the circulation pump.

From the above description it can be seen that the heater according to the invention has a remarkable number of significant advantages when compared with conventional private home furnaces.

(l) The efficiency, that is the fraction of the fuels total heat energy which is converted to useful heat, is extremely high. When burning oil the efficiency of the heater according to the present invention when calculated on a yearly basis is about While the efficiency of presently installed conventional systems in Sweden is only about 50% and the eciency of the newest types of conventional systems is only a'bout 65%.

This higher eciency depends on several effects which are achieved by the present invention. The more important of these effects are as follows:

(a) The insulation losses are reduced by the unique system of insulation.

(b) Insulation losses through three of the four sides of the heating block are utilized by the household.

(c) The heat which is transferred from the furnace up to the accumulator is protected from losses due to chimney draft through the furnace. This is particularly important during long, low-load periods which may occur during the months May through September.

(d) The comparatively small amount of heat remaining in the `furnace after the accumulator is fully heated, is mainly used in the household as a basic amount of heat, emptied by radiator 55.

Effects (a) through (d) above result in high efficiencies also when using other fuels such as gas, wood, coal, coke, etc. The high efiiciency along with certain other oil saving characteristics results according to past tests, in an oil saving up to 35% when compared with conventional furnaces.

(2) The heater may be used with al1 types of fuel, including electrical heating.

(3) The furnace can be replaced separately independent of the accumulator. In this way the heater can also be changed from a simple furnace to a double furnace without distributing the accumulator.

'(4) When using a dou'ble furnace either oil or gas as well as wood or rubbish may be burned simultaneously or alternatively without readjusting the furnace. Due to the large horizontal dimensions of the furnace wood, rubbish, etc. can be burned without first cutting the fuel to small pieces. The burning of wood can always occur at full draft which reduces the amount of deposited soot on the furnace surfaces.

What I claim is:

1. A central heating Iradiator system for heating a house, said heating system comprising a heating unit, said heating unit comprising a furnace section With relatively small water space, and an accumulator section, said accumulator section containing a storage space for an amount of water which is at least ve times the volume of the water contained in the water space in said furnace section, said accumulator storage space being located on top of said furnace section, pipe conduits connecting said accumulator space to said radiator system for conducting hot water from said accumulator space to said radiator system and cooled water from the radiator system to the accumulator space, a rst heat insulating body located between said furnace section and said accumulator section, a valve-less riser pipe connected between said spaces to allow the passage of hot water from said furnace space to said accumulator section, a valve-less return pipe connectedk between said spaces to allow the passage of cooler water from said accumulator storage space to said furnace section, a combustion zone located in said furnace, a flue gas passageway in said furnace connecting said combustion zone with a ue gas outlet, said iiue .gas passageway being separated from said accumulator storage section, a second heat insulating body substantially covering both the furnace section and the accumulator section, plate means disposed in front of the heating unit, and insulation including as parts thereof said rst and second heat insulating bodies, said insulation including parts subtantially covering the unit and filling the space between the unit and the walls of a boiler room in which the unit is located.

2. In a house having Walls dening a substantially closed space, said house having a boiler room forming a part thereof, said boiler room having three walls connected in sequence, the lirst and third walls of the boiler room being connected to the walls of the house proper, the fourth side of the |boiler room being open to the space outside the boiler room, a central heating radiator system for heating said house, said system comprising a heating unit, said heating unit being disposed in said boiler room and beng spaced from the three walls of the boiler room, said heating unit comprising a furnace section with 'relatively small water space, and an accumulator section, said accumulator section containing a storage space for an amount of water which is at least five times the water contained in the water space in said furnace section, said accumulator storage space being located on top of said furnace section, pipe conduits connecting said accumulator space to said radiator system for conducting hot water from said accumulator space to said radiator system and cooled water from the radiator system to the accumulator space, a heat insulating body located between said furnace section and said accumulator section, a valve-less riser pipe connected between said spaces to allow the passage of hot water from said furnace space to said accumulator section, a valve-less return pipe connected between said spaces to :allow the passage of cooler water from said accumulator storage space to said furnace section, a combustion zone located in said furnace, a flue gas passageway in said furnace connecting said combustion zone with a flue gas outlet, plate means disposed in the plane of the opening between the boiler room and the space outside the |boiler room to close the boiler room from the space outside the boiler room, and an insulation including as a part thereof said heat insulating body between said furnace section and said accumulator section, said insulation further including parts filling the space between the unit and the walls of the boiler room and between the unit and said plate means closing the boiler room from the space outside the boiler room.

References Cited UNITED STATES PATENTS 1,115,614 11/1914 Swift 122-2113 1,658,412 2/ 1928 Parker 237-60 FOREIGN PATENTS 670,664 4/ 1952 Great Britain. 824,655 12/ 1959 Great Britain.

95,666 3/ 1960 Norway.

OTHER REFERENCES German application 1,106,945, Donaueschingen, March 1961.

EDWARD J. MICHAEL, Primary Examiner. 

1. A CENTRAL HEATING RADIATOR SYSTEM FOR HEATING A HOUSE, SAID HEATING SYSTEM COMPRISING A HEATING UNIT, SAID HEATING UNIT COMPRISING A FURNACE SECTION WITH RELATIVELY SMALL WATER SPACE, AND AN ACCUMULATOR SECTION, SAID ACCUMULATOR SECTION CONTAINING A STORAGE SPACE FOR AN AMOUNT OF WATER WHICH IS AT LEAST FIVE TIMES THE VOLUME OF THE WATER CONTAINED IN THE WATER SPACE IN SAID FURNACE SECTION, SAID ACCUMULATOR STORAGE SPACE BEING LOCATED ON TOP OF SAID FURNACE SECTION, PIPE CONDUITS CONNECTING SAID ACCUMULATOR SPACE TO SAID RADIATOR SYSTEM FOR CONDUCTING HOT WATER FROM SAID ACCUMULATOR SPACE TO SAID RADIATOR SYSTEM AND COOLED WATER FROM THE RADIATOR SYSTEM TO THE ACCUMULATOR SPACE, A FIRST HEAT INSULATING BODY LOCATED BETWEEN SAID FURNACE SECTION AND SAID ACCUMULATOR SECTION, A VALVE-LESS RISER PIPE CONNECTED BETWEEN SAID SPACES TO ALLOW THE PASSAGE OF HOT WATER FROM SAID FURNACE SPACE TO SAID ACCUMULATOR SECTION, A VALVE-LESS RETURN PIPE CONNECTED BETWEEN SAID SPACES TO ALLOW THE PASSAGE OF COOLER WATER FROM SAID ACCUMULATOR STORAGE SPACE TO SAID FURNACE SECTION, A COMBUSTION ZONE LOCATED IN SAID FURNACE, A FLUE GAS PASSAGEWAY IN 